afs_int32
afs_calc_inum(afs_int32 volume, afs_int32 vnode)
{
- afs_int32 ino, vno = vnode;
+ afs_int32 ino = 0, vno = vnode;
char digest[16];
struct md5 ct;
if (afs_new_inum) {
+ int offset;
MD5_Init(&ct);
MD5_Update(&ct, &volume, 4);
MD5_Update(&ct, &vnode, 4);
MD5_Final(digest, &ct);
- memcpy(&ino, digest, sizeof(afs_int32));
- ino ^= (ino ^ vno) & 1;
- } else {
+
+ /* Userspace may react oddly to an inode number of 0 or 1, so keep
+ * reading more of the md5 digest if we get back one of those.
+ * Make sure not to read beyond the end of the digest; if we somehow
+ * still have a 0, we will fall through to the non-md5 calculation. */
+ for (offset = 0;
+ (ino == 0 || ino == 1) &&
+ offset + sizeof(ino) <= sizeof(digest);
+ offset++) {
+
+ memcpy(&ino, &digest[offset], sizeof(ino));
+ ino ^= (ino ^ vno) & 1;
+ ino &= 0x7fffffff; /* Assumes 32 bit ino_t ..... */
+ }
+ }
+ if (ino == 0 || ino == 1) {
ino = (volume << 16) + vnode;
}
ino &= 0x7fffffff; /* Assumes 32 bit ino_t ..... */